Taurine and tolerance to opioid peptides.

The finding that taurine may possess an ability to inhibit development of tolerance to opioid peptides was demonstrated in the present study. Tolerance was produced in rats by five IVT administrations of DAME during 3 consecutive days. Pretreatment with taurine that had been injected IVT 10 min prior to every administration of DAME suppressed the development of tolerance to both the akinetic and analgetic effects of the peptide. In addition, taurine pretreatment inhibited the induction of hyperlocomotor activity which was observed in tolerant animals as the number of the DAME injections was increased. Tolerance to WDS effects also resulted from the repeated administration of the peptide. However, it could not be concluded from the present experimental condition that taurine affects development of tolerance to WDS, since the amino acid suppressed the induction of WDS from the first injection of DAME.